import json
import logging
import re

from io import StringIO
from textwrap import dedent

from teuthology.orchestra.run import CommandFailedError
from teuthology.orchestra import run
from teuthology.contextutil import MaxWhileTries

from tasks.cephfs.mount import CephFSMount

log = logging.getLogger(__name__)


UMOUNT_TIMEOUT = 300


class KernelMount(CephFSMount):
    def __init__(self, ctx, test_dir, client_id, client_remote,
                 client_keyring_path=None, hostfs_mntpt=None,
                 cephfs_name=None, cephfs_mntpt=None, brxnet=None, config={}):
        super(KernelMount, self).__init__(ctx=ctx, test_dir=test_dir,
            client_id=client_id, client_remote=client_remote,
            client_keyring_path=client_keyring_path, hostfs_mntpt=hostfs_mntpt,
            cephfs_name=cephfs_name, cephfs_mntpt=cephfs_mntpt, brxnet=brxnet)

        self.rbytes = config.get('rbytes', False)
        self.inst = None
        self.addr = None
        self._mount_bin = ['adjust-ulimits', 'ceph-coverage', self.test_dir +\
                           '/archive/coverage', '/bin/mount', '-t', 'ceph']

    def mount(self, mntopts=[], check_status=True, **kwargs):
        self.update_attrs(**kwargs)
        self.assert_and_log_minimum_mount_details()

        self.setup_netns()

        if not self.cephfs_mntpt:
            self.cephfs_mntpt = '/'

        self._create_mntpt()

        retval = self._run_mount_cmd(mntopts, check_status)
        if retval:
            return retval

        self._set_filemode_on_mntpt()

        self.mounted = True

    def _run_mount_cmd(self, mntopts, check_status):
        mount_cmd = self._get_mount_cmd(mntopts)
        mountcmd_stdout, mountcmd_stderr = StringIO(), StringIO()

        try:
            self.client_remote.run(args=mount_cmd, timeout=(30*60),
                                   stdout=mountcmd_stdout,
                                   stderr=mountcmd_stderr, omit_sudo=False)
        except CommandFailedError as e:
            log.info('mount command failed')
            if check_status:
                raise
            else:
                return (e, mountcmd_stdout.getvalue(),
                        mountcmd_stderr.getvalue())
        log.info('mount command passed')

    def _get_mount_cmd(self, mntopts):
        opts = 'norequire_active_mds'
        if self.client_id:
            opts += ',name=' + self.client_id
        if self.client_keyring_path and self.client_id:
            opts += ',secret=' + self.get_key_from_keyfile()
        if self.config_path:
            opts += ',conf=' + self.config_path
        if self.cephfs_name:
            opts += ",mds_namespace=" + self.cephfs_name
        if self.rbytes:
            opts += ",rbytes"
        else:
            opts += ",norbytes"
        if mntopts:
            opts += ',' + ','.join(mntopts)

        mount_cmd = ['sudo'] + self._nsenter_args
        mount_dev = ':' + self.cephfs_mntpt
        mount_cmd += self._mount_bin + [mount_dev, self.hostfs_mntpt, '-v',
                                        '-o', opts]

        return mount_cmd

    def umount(self, force=False):
        if not self.is_mounted():
            self.cleanup()
            return

        log.debug('Unmounting client client.{id}...'.format(id=self.client_id))

        try:
            cmd=['sudo', 'umount', self.hostfs_mntpt]
            if force:
                cmd.append('-f')
            self.client_remote.run(args=cmd, timeout=(15*60), omit_sudo=False)
        except Exception as e:
            self.client_remote.run(
                args=['sudo', run.Raw('PATH=/usr/sbin:$PATH'), 'lsof',
                      run.Raw(';'), 'ps', 'auxf'],
                timeout=(15*60), omit_sudo=False)
            raise e

        self.mounted = False
        self.cleanup()

    def umount_wait(self, force=False, require_clean=False, timeout=900):
        """
        Unlike the fuse client, the kernel client's umount is immediate
        """
        if not self.is_mounted():
            self.cleanup()
            return

        try:
            self.umount(force)
        except (CommandFailedError, MaxWhileTries):
            if not force:
                raise

            # force delete the netns and umount
            self.client_remote.run(args=['sudo', 'umount', '-f', '-l',
                                         self.mountpoint],
                                   timeout=(15*60), omit_sudo=False)

            self.mounted = False
            self.cleanup()

    def wait_until_mounted(self):
        """
        Unlike the fuse client, the kernel client is up and running as soon
        as the initial mount() function returns.
        """
        assert self.mounted

    def teardown(self):
        super(KernelMount, self).teardown()
        if self.mounted:
            self.umount()

    def _find_debug_dir(self):
        """
        Find the debugfs folder for this mount
        """
        pyscript = dedent("""
            import glob
            import os
            import json

            def get_id_to_dir():
                result = {}
                for dir in glob.glob("/sys/kernel/debug/ceph/*"):
                    mds_sessions_lines = open(os.path.join(dir, "mds_sessions")).readlines()
                    client_id = mds_sessions_lines[1].split()[1].strip('"')

                    result[client_id] = dir
                return result

            print(json.dumps(get_id_to_dir()))
            """)

        output = self.client_remote.sh([
            'sudo', 'python3', '-c', pyscript
        ], timeout=(5*60))
        client_id_to_dir = json.loads(output)

        try:
            return client_id_to_dir[self.client_id]
        except KeyError:
            log.error("Client id '{0}' debug dir not found (clients seen were: {1})".format(
                self.client_id, ",".join(client_id_to_dir.keys())
            ))
            raise

    def read_debug_file(self, filename):
        """
        Read the debug file "filename", return None if the file doesn't exist.
        """
        debug_dir = self._find_debug_dir()

        pyscript = dedent("""
            import os

            print(open(os.path.join("{debug_dir}", "{filename}")).read())
            """).format(debug_dir=debug_dir, filename=filename)

        stderr = StringIO()
        try:
            output = self.client_remote.sh([
                'sudo', 'python3', '-c', pyscript
            ], stderr=stderr, timeout=(5*60))

            return output
        except CommandFailedError:
            if 'no such file or directory' in stderr.getvalue().lower():
                return None
            raise

    def get_global_id(self):
        """
        Look up the CephFS client ID for this mount, using debugfs.
        """

        assert self.mounted

        mds_sessions = self.read_debug_file("mds_sessions")
        assert mds_sessions 

        lines = mds_sessions.split("\n")
        return int(lines[0].split()[1])

    @property
    def _global_addr(self):
        if self.addr is not None:
            return self.addr

        # The first line of the "status" file's output will be something
        # like:
        #   "instance: client.4297 (0)10.72.47.117:0/1148470933"
        # What we need here is only the string "10.72.47.117:0/1148470933"
        status = self.read_debug_file("status")
        if status is None:
            return None

        instance = re.findall(r'instance:.*', status)[0]
        self.addr = instance.split()[2].split(')')[1]
        return self.addr;

    @property
    def _global_inst(self):
        if self.inst is not None:
            return self.inst

        client_gid = "client%d" % self.get_global_id()
        self.inst = " ".join([client_gid, self._global_addr])
        return self.inst

    def get_global_inst(self):
        """
        Look up the CephFS client instance for this mount
        """
        return self._global_inst

    def get_global_addr(self):
        """
        Look up the CephFS client addr for this mount
        """
        return self._global_addr

    def get_osd_epoch(self):
        """
        Return 2-tuple of osd_epoch, osd_epoch_barrier
        """
        osd_map = self.read_debug_file("osdmap")
        assert osd_map

        lines = osd_map.split("\n")
        first_line_tokens = lines[0].split()
        epoch, barrier = int(first_line_tokens[1]), int(first_line_tokens[3])

        return epoch, barrier

    def get_op_read_count(self):
        buf = self.read_debug_file("metrics")
        if buf is None:
            return 0
        else:
            return int(re.findall(r'read.*', buf)[0].split()[1])
